The German Franz Morell and his son-in-law, engineer Erich Rasche, invented bioresonance therapy in 1977 . They marketed it as MORA-therapy - named after themselves (MOrell RAsche). This method is based on former radionics introduced in the USA during the 1920s. It is not part of scientific medicine, due to an absence of evidence.[2] Some of the machines contain an electronic circuit measuring skin-resistance, akin to the E-Meter used by Scientology, which the bioresonance creators sought to improve.[3] (Franz Morell had links with Scientology.[4]) Bioresonance has nothing in common with biofeedback concepts.

Descriptions are obscure.[5] Practitioners usually apply electrodes, linked to a box, to the patient's skin. According to the manufacturer of these devices, they emit alternating currents which are healing. The manufacturers describe cells as objects having a natural resonance (i.e. bio-resonance.) Such frequencies are not viewed as efficacious by modern medicine.

Due to the electrical interference of the signals generated by everyday equipment and the range of frequencies utilised, the response is sometimes read through an extended period, in order to average it and to increase the accuracy of the results.[citation needed] In some of these devices a modern signal processing technique, usually PC-based, is able to analyse the multiple parameters of the response and interpret the results. The analyst is then supposedly able to make an assessment/summary of the physical and mental health of the patient.

Practitioners also say they can treat disease using this therapy, claiming they can stimulate a change of bioresonance in the cells, reversing the change caused by the disease. The devices would need to be able to isolate and pinpoint pathogens' responses from the mixture of responses the device receives via the electrodes. Transmitting these transformed signals over the same electrodes is claimed[by whom?] to generate healing signals that have the curative effect. With this method of diagnosis and treatment, practitioners claim to be able to detect and cure a variety of diseases and addictions without drugs. The given mode of operation (pathogenic signals in opposition to healthy ones) is linked to similar concepts in Traditional Chinese Medicine, especially acupuncture.

Proven cases of online fraud have occurred,[15] with a practitioner making false claims that he had the ability to cure cancer, and that his clients did not need to follow the chemotherapy or surgery recommended by medical doctors, which can be life-saving. Ben Goldacre ridiculed the BBC when it reported as fact a clinic's claim that the treatment had the ability to stop 70% of clients smoking, a better result than any conventional therapy.[16]

In the United States of America the U.S. Food and Drug Administration (FDA) classifies "devices that use resistance measurements to diagnose and treat various diseases" as Class III devices, which require FDA approval prior to marketing. Some of these devices have been banned[by whom?] from the US market.[17]